Incorrect punctuation marks can change the entire meaning of a sentence! The main punctuation marks, along with their usage are discussed below:

The word 'punctuation' is derived from the Latin word 'punctum' or point, and refers to the use of putting in Points or Stops in writing, in order to increase readability. There are quite a few punctuation marks, each having a separate usage.

The other main punctuation marks, along with their usage are discussed below:

Comma (,)

The comma, which represents the shortest pause, has various uses as listed below:

1. Used in writing lists, to separate a series of words, phrases, or independent clauses.

Example: I am taking art history, Russian literature, microeconomics, and macroeconomics next semester. (A comma used before 'and' to clarify the sentence is called an Oxford comma or a serial comma. The last comma helps the reader understand that macroeconomics is one course, while microeconomics is another separate course.)

2. To separate non-restrictive or non-essential words or phrases, which are appearing at the beginning, middle or end of a sentence, from the main clause.

Examples: In my opinion, the movie was more compelling than the book. (To separate phrase at beginning)The hotel, once we finally found it, was very nice. (To separate phrase in middle)We will not be attending the reception, however. (To separate word at end)

But if the word ending the sentence is an adverb, which is essential to the meaning of the sentence, then no comma should be used.

Example: We took the train instead.

3. To separate multiple adjectives describing the same noun.

Example: The wine offered a fragrant, captivating bouquet.This is a very, very violent movie. (used in case of repeated adjectives or adverbs placed for greater emphasis)

However, if the consecutive adjectives do not individually describe the noun, they should not be separated by a comma.

Example: He held a bright red balloon. (The balloon is bright red, not bright and red.)

4. When using 'which'. Comma is not used when using 'that'.

Examples: John's cars, which are leased, are never kept clean. (The sentence refers to all of John's cars and says they are dirty. The information that the cars are leased is non-essential, and so, enclosed in commas.)John's cars that are leased are never kept clean. (In this case, the dirty cars are specifically those that John leased.)

5. When directly addressing someone, the person's name or title should be set off with commas.

Examples: Thank you, Governor, for your support.We could not have done it without you, Lisa.

6. When a degree or certification is shown after a person's name, it should be set off with commas.

Example: Tom Roberts Jr., MD, FACS, will be the keynote speaker at next year's conference.

7. When writing dates, the different segments are separated by commas, except for the day of the month and the name of the month.

Examples: The store closed its doors for good on Wednesday, October 15, 1958.Her arrival on April 10, 1988, was considered a turning point for the company.The store closed its doors for good in October 1958. (No comma needed between year and month when there are only two elements in the date)

8. Used to separate geographical elements when describing location. The final geographical element is also followed by a comma when it appears in the middle of the sentence.

Example: His family moved from Bristol, England, to Portsmouth, New Hampshire, when he was eight.

9. To increase the readability of numbers.

Example: We sold 1,270 rare books last year; the most expensive sold for $5,255.50.

10. To indicate where a word (usually a verb) has been omitted.

Example: Rama received a fountain pen; Hari, a watch.

11. To set off a direct quotation from the rest of the sentence.

Example: "Go then," said the ant, "and dance winter away."

Question Mark (?)

The following are the rules of using a question mark:

1. The question mark is used at the end of a direct question.Example: Have you completed your homework?

2. The question mark is not used after an indirect question.Example: He asked me whether I had completed my homework.

Exclamation Mark (!)

The exclamation mark is used in the following cases:

1. Used sentences expressing a sudden emotion or wish.Example: What a terrible fire this is!

2. Used after interjections.Examples: Alas! Our teacher is no more.Hurrah! We won.

3. In the case of the interjection 'O', the exclamation mark is placed after the noun or at the end of the sentence.Examples: O Lord! In you I put my trust.O, what a fall there was, my countrymen!

Inverted Commas or Quotation Marks (" ")

Inverted commas or quotation marks are used in the following cases:

1. Inverted Commas are used to enclose the exact words of a speaker.Example: "I would rather die," he exclaimed, "than join the oppressors of my country."

2. Inverted Commas are used to enclose a quotation.Example: Babar is said by Elphinstone to have been "the most admirable prince that ever reigned in Asia."

3. If a quotation occurs within a quotation, it is marked by single inverted commas.Example: "You might as well say," added the March Hare, "that 'I like what I get' is the same thing as 'I get what I like'."

Apostrophe (')

The Apostrophe is used in the following cases:

1. To show the omission of a letter or letters.Examples: Don't, e'er, I've.

2. To denote the possessive case of nouns.Examples: Ravi's hat, the dog's food.

3. To form the plural of letters and figures.Examples: Dot your i's and cross your t's.Add two 5 's and four 2 's.